Add sub action button.

Assets/Cryville/Crtr/Browsing/UI/ActionBar.cs

@@ -7,13 +7,20 @@ namespace Cryville.Crtr.Browsing.UI {
 	internal class ActionBar : MonoBehaviour {
 		[SerializeField]
 		ActionButton m_mainButton;
+		[SerializeField]
+		ActionButton m_subButton;
 
 		public void Load(ResourceBrowser browser, IReadOnlyCollection<IResourceAction> actions) {
 			var enumerator = actions.OrderBy(i => i.Priority).GetEnumerator();
 			if (enumerator.MoveNext()) {
 				gameObject.SetActive(true);
 				m_mainButton.Load(browser, enumerator.Current);
-				// TODO Subactions
+				if (enumerator.MoveNext()) {
+					m_subButton.Load(browser, enumerator.Current);
+				}
+				else {
+					m_subButton.Clear();
+				}
 			}
 			else {
 				m_mainButton.Clear();